Foldable window blind

ABSTRACT

A foldable window blind includes a cord-winding device, a foldable curtain suspended from the cord-winding device, two vertical rows of positioning members, and a counterweight device. The cord-winding device includes a rail, a spool unit, and two pull cords suspended from the rail and biased to be wound on the spool unit. Each of the positioning members is sleeved movably on a corresponding one of the pull cords, and is fastened to the curtain. The counterweight device is fastened to a lower end of the curtain, and is movable upwardly to an upper limit position so as to fold the curtain to form a plurality of curtain folds. When the counterweight member is disposed at the uppermost position, a lower end of the counterweight device is located below lower ends of the curtain folds.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to a window blind, and more particularly to a foldable window blind that includes a curtain and a counterweight device, which is movable vertically to fold the curtain.

2. Description of the Related Art

Referring to FIGS. 1 and 2, a conventional foldable window blind is shown to include: a rail 21; a foldable curtain 22 suspended from the rail 21; two vertical rows of cord-retaining rings 23 fastened to a rear side surface of the curtain 22; a spring-loaded spool unit 24 disposed on the rail 21; two pull cords 25 suspended respectively from two end portions of the rail 21 and biased to be wound on the spool unit 24, the pull cords 25 extending respectively through the two rows of the cord-retaining rings 23; a vertical row of horizontal suspended rods 26 fastened to a front side surface of the curtain 22; and a horizontal counterweight rod 27 connected fixedly to a lower end of the curtain 22. By virtue of gravity, the counterweight rod 27 applies a downward pulling force to the curtain 22 so as to balance an upward pulling spring force of the spool unit 24 applied to the curtain 22. As such, when no external force is applied to the counterweight rod 27, the counterweight rod 27 can be maintained at any desired position relative to the rail 21 by balance between the upward pulling spring force of the spool unit 24 and the downward pulling force of the counterweight rod 27.

The curtain 22 is divided by the cord-retaining rings 23 into three curtain sections 221 that are arranged one above the other. Each of the suspended rods 26 is located at an upper end, lower end, or middle portion of the corresponding curtain section 221, and has a length substantially equal to that of horizontal sides of the curtain 22. When the counterweight rod 27 is moved upwardly to an uppermost position shown in FIG. 2, each of the curtain sections 221 is folded to form a curtain fold 222, and is disposed in front of the counterweight rod 27. The curtain folds 222 are arranged one behind the other. The conventional foldable window blind is disadvantageous in that, when located at the uppermost position, the counterweight rod 27 is disposed behind the curtain folds 222, and has a lower end that is much higher than that of the lowermost curtain fold 222. As such, it is difficult to move the counterweight rod 27 downwardly from the uppermost position. This results in inconvenient use of the conventional foldable window blind.

SUMMARY OF THE INVENTION

The object of this invention is to provide a foldable window blind that includes a counterweight device, which can be moved vertically with ease.

According to this invention, a foldable window blind includes a cord-winding device, a foldable curtain, a positioning unit, and a counterweight device. The cord-winding device includes a rail, a spool unit disposed on the rail, and two spaced-apart pull cords suspended from the rail and biased to be wound on the spool unit. The curtain is suspended from the cord-winding device, has an upper end fastened to the rail, and is disposed in front of the pull cords. The positioning unit includes two symmetrical rows of positioning members that are aligned respectively with the two pull cords. Each row of the positioning members is arranged one above the other. Each of the positioning members is sleeved movably on a corresponding one of the pull cords, and is fastened to the curtain. The counterweight device includes two vertical supporting rods fastened to a lower end of the curtain. The supporting rods are spaced apart from each other along a horizontal direction, and are interconnected fixedly. The counterweight device is movable upwardly relative to the rail to an upper limit position so as to fold the curtain to form a plurality of curtain folds in front of the counterweight device. Each of the positioning members is disposed between two adjacent ones of the curtain folds. When the counterweight device is disposed at the uppermost position, a lower end of the counterweight device is disposed below lower ends of the curtain folds so as to allow for convenient access thereto. As such, the counterweight device can be moved vertically with ease.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other features and advantages of this invention will become apparent in the following detailed description of the preferred embodiments of this invention, with reference to the accompanying drawings, in which:

FIG. 1 is a perspective view of a conventional foldable window blind;

FIG. 2 is a schematic fragmentary side view of the conventional foldable window blind, illustrating how a curtain is folded;

FIG. 3 is a perspective view of the first preferred embodiment of a foldable window blind according to this invention;

FIG. 4 is a schematic fragmentary side view of the first preferred embodiment, illustrating how a curtain is folded;

FIG. 5 is a perspective view of the second preferred embodiment of a foldable window blind according to this invention;

FIG. 6 is a top view of a positioning member of the second preferred embodiment; and

FIG. 7 is a schematic fragmentary side view of the second preferred embodiment, illustrating how a curtain is folded.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Before the present invention is described in greater detail in connection with the preferred embodiments, it should be noted that similar elements and structures are designated by like reference numerals throughout the entire disclosure.

Referring to FIGS. 3 and 4, the first preferred embodiment of a foldable window blind according to this invention is shown to include a cord-winding device 3, a foldable curtain 4, a positioning unit 5, a vertical row of spaced-apart horizontal suspended rods 6, and a counterweight device 7.

The cord-winding device 3 includes a horizontal rail 31, a spring-loaded spool unit 32 disposed on the rail 31 in a known manner, and two spaced-apart pull cords 33 suspended respectively from two end portions of the rail 31 and biased to be wound on the spool unit 32 in a known manner.

The curtain 4 is made of a fabric, is suspended from the cord-winding device 3, and is disposed in front of the pull cords 33. An upper end of the curtain 4 is fastened to the rail 31 in a known manner.

The positioning unit 5 includes two symmetrical vertical rows of positioning members 51 disposed behind the curtain 4 and aligned respectively with the two pull cords 33, two pushing rings 52 connected respectively and fixedly to lower ends of the pull cords 33, and two connecting bands 53. The connecting bands 53 have upper ends fastened respectively to the pushing rings 52, and lower ends fastened to the counterweight device 7. Each vertical row of the positioning members 51 is arranged one above the other. Each of the positioning members 51 is fastened to the curtain 4, and has an annular rear end that is sleeved movably on the corresponding pull cord 33. When the curtain 4 is in a completely unfolded state, as shown in FIG. 3, it is divided by each vertical row of the positioning members 51 into three curtain sections 40 that are arranged one above the other. Alternatively, the pushing rings 52 and the connecting bands 53 can be omitted such that the counterweight device 7 is fastened directly to the lower ends of the pull cords 33.

The suspended rods 6 are attached fixedly to a front side surface of the curtain 4 in a known manner. Each of the suspended rods 6 is located at an upper end, lower end, or middle portion of the corresponding curtain section 40, and has a length substantially equal to that of horizontal sides of the curtain 4. Each of the curtain sections 40 is further divided by one of the suspended rods 6, which is located at the middle portion thereof, into two half-curtain sections 401.

The counterweight device 7 includes a horizontal connecting rod 71 connected fixedly to the lower ends of the connecting bands 53, two vertical supporting rods 72 connected fixedly to and extending respectively and downwardly from two opposite ends of the connecting rod 71, and a horizontal counterweight rod 73 having two opposite ends connected respectively and fixedly to lower ends of the supporting rods 72. The supporting rods 72 are fastened to a lower end of the curtain 4, are spaced apart from each other along a horizontal direction, and have a length larger than that of vertical sides of the half curtain sections 401. The weight of the counterweight device 7 can balance the upward pulling spring force of the spring-loaded spool unit 32 applied to the curtain 4 so that the counterweight device 7 can be maintained at any desired position relative to the rail 31. As such, the vertical position of the counterweight device 7 can be adjusted in a known manner.

When the counterweight rod 73 is pushed upwardly, the spool unit 32 moves the pull cords 33 upwardly. At the same time, the pushing rings 52 move the positioning members 51 upwardly so as to fold the curtain 4. When the counterweight device 7 is moved to an uppermost position shown in FIG. 4, each of the curtain sections 40 is folded such that the rear side surfaces of the half curtain sections 401 of each of the curtain sections 40 abut against each other to form a curtain fold 44. As a result, each of the positioning members 51 is disposed between two curtain folds 44. The curtain folds 44 are arranged one behind the other, and are disposed in front of the counterweight device 7.

As such, when the counterweight device 7 is disposed at the uppermost position shown in FIG. 4, a lower end of the counterweight device 7 is disposed below lower ends of the curtain folds 44, and therefore can be accessed conveniently. That is, the counterweight device 7 can be moved upwardly with ease.

Referring to FIGS. 5, 6, and 7, the second preferred embodiment of a foldable window blind according to this invention is shown to include a cord-winding device 3, a foldable curtain 4, a positioning unit 5, and a counterweight device 7.

The cord-winding device 3 is similar in construction to that of the first embodiment, and includes a rail 31, a spring-loaded spool unit 32, and two pull cords 33.

The curtain 4 includes a vertical row of horizontally extending bamboo strips 41 that are interconnected by thread members 42.

The positioning unit 5 includes six positioning members 51 that are arranged in two symmetrical vertical rows. The curtain 4 is divided by each vertical row of the positioning members 51 into three curtain sections 40 that are arranged one above the other. Each of the positioning members 51 is generally S-shaped, as shown in FIG. 6, and has a front half portion 511 and a rear half portion 512. Each of two uppermost ones of each vertical row of the positioning members 51 is hooked removably on the corresponding thread member 42 at the front half portion 511, and is sleeved movably on the corresponding pull cord 33 at the rear half portion 512. Because the front half portion 511 of each of the positioning members 51 can be hooked on the corresponding thread member 42 between any two adjacent ones of the bamboo strips 41, the positions of the positioning members 51 relative to the curtain 4 can be adjusted.

The counterweight device 7 includes two vertical supporting rods 72 and a horizontal counterweight rod 73. The supporting rods 72 are spaced apart from each other along a horizontal direction, and are fastened to a lower end of the curtain 4. The counterweight rod 73 is connected fixedly to lower ends of the supporting rods 72. Each of the supporting rods 72 has a length larger than half of that of vertical sides of the curtain sections 40. Each of the supporting rods 72 has a plurality of holes 721 formed therethrough and arranged one above the other. The holes 721 in one of the supporting rods 72 are aligned horizontally and respectively with those in the other of the supporting rods 72. The lowermost one of each vertical row of the positioning members 51 extends through a selected one of the holes 721 in the corresponding supporting rod 72 so as to allow for adjustment of a length of the curtain 4 located under the lowermost positioning member 51.

When the counterweight device 7 is moved to an uppermost position as shown in FIG. 7, a lower end of the counterweight device 7 is located below the curtain sections 40. Therefore, the object of this invention can be achieved.

With this invention thus explained, it is apparent that numerous modifications and variations can be made without departing from the scope and spirit of this invention. It is therefore intended that this invention be limited only as indicated by the appended claims. 

1. A foldable window blind comprising: a cord-winding device including a rail, a spool unit disposed on said rail, and two spaced-apart pull cords suspended from said rail and biased to be wound on said spool unit; a foldable curtain suspended from said cord-winding device and having an upper end fastened to said rail, said curtain being disposed in front of said pull cords; a positioning unit including two symmetrical vertical rows of positioning members that are disposed behind said curtain and that are aligned respectively with said two pull cords, each row of said positioning members being arranged one above the other, each of said positioning members being sleeved movably on a corresponding one of said pull cords and being fastened to said curtain; and a counterweight device including two vertical supporting rods spaced apart from each other along a horizontal direction and fastened to a lower end of said curtain, said supporting rods being interconnected fixedly, said counterweight device being movable upwardly relative to said rail to an upper limit position so as to fold said curtain to form a plurality of curtain folds in front of said counterweight device, each of said curtain folds being arranged one behind the other such that each of said positioning members is disposed between two adjacent ones of said curtain folds, said counterweight device having a lower end that is disposed below lower ends of said curtain folds when said counterweight device is disposed at said uppermost position.
 2. The foldable window blind as claimed in claim 1, wherein said curtain is made of a fabric, said foldable window blind further including a vertical row of spaced-apart horizontal suspended rods that are attached fixedly to said curtain.
 3. The foldable window blind as claimed in claim 1, wherein a position of each of said positioning members relative to said curtain is adjustable.
 4. The foldable window blind as claimed in claim 3, wherein each of said positioning members is generally S-shaped, and has a front half portion hooked removably on said curtain, and a rear half portion sleeved movably on the corresponding one of said pull cords.
 5. The foldable window blind as claimed in claim 4, wherein said curtain includes a vertical row of interconnected horizontally extending bamboo strips.
 6. The foldable window blind as claimed in claim 1, wherein each of said supporting rods has a plurality of holes formed therethrough that are arranged one above the other, said holes in one of said supporting rods being aligned respectively with said holes in the other of said supporting rods, a lowermost one of each vertical row of said positioning members extending into a selected one of said holes in a corresponding one of said supporting rods so as to allow for adjustment of a length of said curtain located under said lowermost one of each vertical row of said positioning members.
 7. The foldable window blind as claimed in claim 1, wherein said counterweight unit further includes a horizontal counterweight rod interconnecting fixedly lower ends of said supporting rods.
 8. The foldable window blind as claimed in claim 7, wherein said counterweight unit further includes a horizontal connecting rod interconnecting fixedly upper ends of said supporting rods, lower ends of said pull cords being fastened to said horizontal connecting rod. 